Moulding compounds based on thermosetting material are, for instance, Sheet Moulding Compounds (SMC), Bulk Moulding Compounds (BMC), Dough Moulding Compounds (DMC) and free-flowing solid moulding compounds, such as moulding powders, moulding granulates or moulding flakes, etc.
Related processing techniques are known from the Kunststoffhandbuch, volume 8, Polyester by Vieweg and Goerden, pages 482, 491 and 495 and from the papers read during the `13th Offentliche Jahrestag der Arbeitsgemeinschaft Verstarkte Kunststoffen` held at Freudenstadt from Oct. 5th till 7th 1976.
These moulding compounds can be processed by injection moulding, transfer moulding, compression moulding, pulltrusion, combinations of injection moulding and compression moulding, etc.
In the application of such moulding compounds great value is attached to the non-porousness and smoothness of the surface. The automobile industry, for instance, makes demands on the non-porousness and smoothness of the surface, which must at least come up to the quality of steel. At the same time the costs of the proposed solutions for the surface problems must also be dealt with, since these must not be too high. There must be no fibres, e.g. glass fibres, direct at the surface of moulding compounds that must conform with high standards in respect of the surface.